If you want to avoid the Windows notification sounds to be sent to the output used for measurements, you can either turn the sounds off or play them using another sound card (if you have more than one card in your system). To play the notification sounds using another sound card, you need to set this sound card as the preferred device. You can turn off the system sounds as explained below.
Click the button to find the Control Panel (you may have to select Settings first). Then double-click on the folder Sounds and Audio Devices shown below.
(It may be named Sounds only).
Then click on the list field under Sound schemes. When the list appears, choose No Sounds as shown below.
If you wish to play the notification sounds using another sound card instead of turning them off, click the Audio tag shown in the figure above and select the preferred sound device.
Open the Control Panel, find the multimedia settings. Find Settings and choose No sounds.
Open the Control Panel, click the Sounds icon. Find the dialog box Sound Properties. Click Windows under Events.